What is a crucial prerequisite for publishing a report to Power BI Service from Power BI Desktop?

To successfully publish a report to the Power BI Service from Power BI Desktop, saving the report is essential. When you save your report in Power BI Desktop, it ensures that all your configurations, visuals, data connections, and model definitions are stored in the file. This saved report file is then what gets published to the Power BI Service.

Without saving the report, there would be no file to publish, which would result in an error or failure to publish the intended report. This step guarantees that users can access the most recent version of your work in the Power BI Service, allowing for collaboration and sharing of insights with others.

The other options do not align with the necessary steps for publication. For instance, deleting the report or having to open it in the Power BI Service prior to publishing does not pertain to the basic requirements for publishing. Additionally, there is no specific size requirement for reports in this context; rather, successful publishing depends solely on saving the report first.